44results about How to "The reaction method is simple" patented technology

The invention discloses a method for synthesizing L-theanine through an enzyme process, and belongs to the biotechnical field. The method is characterized in that a gamma-glutamyltranspeptidase gene is obtained through chemical synthesis, a gene engineering bacterium over-expressing gamma-glutamyltranspeptidase is constructed by treating Escherichia coli as a host bacterium, glutamine and ethylamine hydrochloride having different concentrations are acted by a recombinase, and theanine is efficiently produced at a temperature of 37-50DEG C under a pH value of 9.5-10.5. The enzyme source preparation process has the advantages of simplicity, low cost, and large enzyme amount, and the theanine production method has the advantages of simplicity, high conversion rate, high output, short time and the like, and is in favor of the industrialized amplification production.

The invention relates to a synthetic method for a compound in the technical field of medicine and chemical engineering, and particularly relates to a novel synthetic method for tadalafil. The synthetic method comprises the steps of: 1) condensing an initial raw material which is D-tryptophan (I) and methylamino acetonitrile (II) or salt thereof to obtain a compound as shown in a formula III; 2) carrying out Pictet-Spengler cyclization reaction on the compound as shown in the formula III and heliotropin and carrying out crystallization to obtain a compound as shown in a formula V; and 3) hydrolyzing the compound V under an acidic or alkaline condition by cyano and then condensing the compound to obtain the target product tadalafil (VI). The formula is shown in the description. In the synthetic method provided by the invention, chemical raw materials which are great in toxicity, severe in environmental pollution and flammable and combustible such as thionyl chloride, chloroacetyl chloride, methylamine and the like. The novel synthetic method for tadalafil provided by the invention is simple in reaction method, convenient to operate and high in yield.

The invention provides a preparation method of a 2,5-dialkoxyl dihydrofuran compound. The preparation method comprises the following steps: adding a furan compound shown by a formula I, alkyl alcohol shown by a formula III and an acid-binding agent into a reactor, stirring to react with chlorine, keeping the reaction temperature to be (-25)-25 DEG C, and reacting to obtain a 2,5-dialkoxyl dihydrofuran compound shown by a formula II, wherein in the formulas, R1, R2, R3 and R4 are independent hydrogen, halogen and C1-C5 alkyl, and R1 is a C1-C12 alkyl. The method provided by the invention is less in investment, low in energy consumption and high in efficiency; the reaction method is simple, and the operation is convenient and easy to implement; the raw materials are low in price, easy to obtain, and low in production cost; a byproduct is salt and can meet requirements on environmental protection; and the preparation method is suitable for performing industrial large-scale production of the 2,5-dialkoxyl dihydrofuran compound. Particularly, when a phase transfer catalyst is added into the method provided by the invention, the method also has the advantage that the yield of a target product is obviously improved.

The invention relates to a method for synthesizing a short-chain flavor ester with cutinase and belongs to the technical field of enzyme engineering and fermentation engineering. According to the method, pichia pastoris serves as a host bacterium to build a genetically engineered bacterium of overexpressed cutinase, the genetically engineered bacterium is induced to generate cutinase through fermentation, and enzyme activity of cutinase in supernatant of fermentation liquor reaches 420 U / mL. The recombinant enzyme is further used to produce the short-chain flavor ester in an organic phase, Chinese rice wine aging acceleration and baijiu solid fermentation. The method has the advantages that an enzyme source preparation method is simple, cost is low, enzyme quantity is large, a short-chain flavor ester production method is simple, the conversion rate is high, the yield is high and time is short, and industrial enlarged production is facilitated.

The invention provides a method for determining the residual quantity of sulfur dioxide in Chinese herbal medicines. The method comprises the following operation steps: (1) taking the Chinese herbal medicines to be determined, and preparing a test solution; (2) taking sulfite as a reference substance, and preparing a reference substance solution; (3) respectively taking the test solution and the reference substance solution, adding an ortho-phthalaldehyde solution and an ammonium salt solution for reaction in a buffer solution, standing after the reaction is over and stopped, and determining the residual quantity of sulfur dioxide in Chinese herbal medicines by a fluorescence derivatization method. According to the method for determining the residual quantity of sulfur dioxide in Chinese herbal medicines, the residual quantity of sulfur dioxide in Chinese herbal medicines can be accurately and fast determined, and the reaction method is simpler and more convenient and is higher in practicability while the accuracy is equivalent to that of a pharmacopoeia method.

The invention discloses a preparation method of interlocking micro-capsules based on a polymer with a high specific surface area and having a hierarchical porous structure. The method comprises the following steps: modifying a silicon dioxide colloid crystal template, performing controlled graft of a polymer chain segment by surface-initiated atom transfer radical polymerization and double-bond radical polymerization, crosslinking a linear polymer chain segment by using a friedel-crafts crosslinking method, and removing the silicon dioxide colloid crystal template, thus preparing interlocking micro-capsules based on a polymer with a high specific surface area and having a hierarchical porous structure. Through a controlled graft polymer layer, a certain gap is formed in an area which is fully filled before, thereby reducing the mass and forming more mass transfer ways. By adopting a friedel-crafts crosslinking and pore-forming technology, capsule walls made of a polymer material are cross-linked to form micro-pores and meso-pores; the material formed by adopting a friedel-crafts self-crosslinking technology is high in specific surface area, thereby greatly improving the application performance; the capsule cavities at micro-pore, meso-pore and large-pore levels, communication windows formed among interlocking micro-capsules and gaps among the micro-capsules present a hierarchical porous interlocking structure on the whole.

The invention discloses an amino acid amide compound and a preparation method thereof. Amino acid protected by FMOC and an acyl chloride reagent react to produce amino acid acyl chloride which is dissolved into a solvent with an appropriate polarity and reacts with a simple compound with primary amine and secondary amine so that the prepared amino acid amide compound can precipitate once forming in the reaction process, thereby reducing the contact of the FMOC and the amine; the whole process is short in the reaction time and fast in speed, thereby preventing the de-protection and realizing that the amino acid protected by the FMOC reacts with the simple amine on the premise without removing protective group; and the yield is up to more than 93 percent. The reaction method is simple, and has high efficiency and clean products as well as easy post treatment.